What it is and where it fits
The Siemens SENTRON 3VA1040-4ED32-0KA0 is a 3-pole molded case circuit breaker (MCCB) rated for 40 A continuous at 40 °C, designed for line protection in distribution panels. It carries a TM210 thermal-magnetic overcurrent release and includes an integrated shunt trip (STL) auxiliary release for remote tripping. The insulation voltage is rated at 800 V. Panel footprint is 130 mm tall, 76.2 mm wide, 70 mm deep.
Breaking capacity — what those voltage-specific ratings mean
This MCCB delivers 121 kA at 240 VAC, 75.6 kA at 415 VAC, 52.5 kA at 440 VAC, and 11.9 kA at both 500 VAC and 690 VAC. Those numbers aren't just for show — they tell you the maximum fault current this breaker can safely interrupt at each system voltage. On a 480 V panel with 65 kA available fault current, this breaker has headroom. At 690 V, the 11.9 kA rating is the limiting factor; if your upstream transformer can push more than that, you need a higher-rated frame or a current-limiting fuse ahead of it.
Thermal derating — real-world current capability
The 40 A rating holds steady from 40 °C up to 50 °C ambient. Above that, it starts to step down: 38.4 A at 55 °C, 37.6 A at 60 °C, 36.8 A at 65 °C, and 36 A at 70 °C. If your panel runs hot — say, 55 °C inside the enclosure — you're losing about 4% of your headroom. Still enough for a 40 A feeder if the load is continuous at 32 A or so, but worth factoring into the wire sizing and the load schedule.
What's on the van — integration notes
The shunt trip (STL) release allows remote tripping via an external signal. The TM210 release is thermal-magnetic with no electronic adjustment. No communication function or ground-fault monitoring on this variant. The 70 mm depth fits standard enclosures.